False alarm?

I was working away on my new-to-me Windows 11 Zbook laptop, when all of a sudden, quite unsolicited, something which looked like McAfee sprang into life and told me that I had a serious problem. All very alarming.

However, rather than press the buy button, I went into Settings and checked the status of Windows Defender. It looked to be alive and well, but I did a quick scan just to be sure, a quick scan which took about as long as the McAfee one - but which found nothing.

Next stop the sometimes irritating new-model Bing, the Microsoft answer to Bard, also apt to spring into unsolicited life. With the following result:

Question: McAfee popped up on my Windows 11 PC and announced that I had 5 trojans. I have Windows Defender running and a quick scan did not turn anything up. Do I need to do anything else? 

Answer: Hi, this is Bing. It sounds like you might have encountered a false positive from McAfee. A false positive is when an antivirus program mistakenly identifies a harmless file as malware. This can happen for various reasons, such as signature-based or heuristics-based detection methods...

For the moment, I shall let the matter rest. Not something which ever happened, as least as far as I can recall, in the Windows 10 Elitebook world. But all very tiresome.

PS: a fairly helpful answer from Bing. But if I had been marking it as an answer to an examination question, I would have marked him down for not having read the question very carefully. I tried the same question on Bard and I thought that he did rather better - even though the first part of his advice did depend on having the offending pop-up in front of one, which is no longer the case. Prompted, he went on to explain the situation with pdf files, with the combination of Acrobat and Defender providing some protection. With a takeaway being that I am perhaps a bit too relaxed about downloading and opening pdf's from websites that I do not know.